Electric circuit for controlling traffic signals



March 25, 1952 o. J. BLANCHET ELECTRIC CIRCUIT FOR CONTROLLING TRAFFICSIGNALS Filed Nov. 12, 1947 I20 V. AC.

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Patented Mar. 25, 1952 UNITED STATES PATENT OFFICE ELECTRIC CIRCUIT FORCONTROLLING TRAFFIC SIGNALS Claims.

This invention relates to electric supply and control circuits for thelamp bulbs of traffic signal casings, and especially to a circuit fortraffic signal casingscontaining spare lamp bulbs and means for shiftinga new lamp bulb into operative position to replace a bulb which has beenburnt out.

The principal object of this invention is to provide an electric circuithaving devices therein for automatically completing a circuit through amotor, disposed to rotate a carrier in which several spare lamps aremounted, so as to put a fresh lamp into connection with the supplyconductors when necessary, and so arranged as to work properly inconjunction with the regular circuit which causes the stop and go lightsto glow in succession for the period necessary to produce safe traificconditions.

A further object is to provide a circuit for a traffic signal unithaving extra lamp bulbs for relay purposes, designed so as to energizean extra signal when all spare lamp bulbs are exhausted; thus givingwarning that the unit must be equipped with new lamps at once to avoidsuspension or interruption of service.

The nature and advantages of the invention are made plain in thefollowing description and the characteristics are defined in theappended claims. But the disclosure is explanatory only and I may adoptvariations in details without deviating from the essential featureswherein the invention resides.

On the drawings,

Figure 1 shows an outline of a supply and controlling circuit accordingto this invention, with spare lamps to be shifted into operativeposition when required; and

Figure 2 shows a panel carrying operating members in said circuit.

The numeral l indicates the terminal of the bulb of the same group intoposition to be energized. Thus interruption of the operation of thetraffic signal unit is prevented. Whenever a red lamp is to beilluminated, current is delivered to terminal 4, conductor 6 to a closedswitch I; andfrom the switch the same conductor is continued to theterminals r-r of the lamp RI which is then in circuit. The currentreturns by Way of wire 8, a series transformer enters this shunt circuitto energize the secondary of the transformer 12, the circuit of whichcontains a half-wave rectifier l3 and a coil l4 bridged by a condenser.The coil is connected by a plunger, not shown, to pull a switch memberI5, normally held open by any suitable means chief supply lead 2, and 3the terminal of the return wire of the supply circuit. A mechanicalcircuit controller or timer, not shown, connects the supply lead 2alternately to the terminals 4 and 5 to energize one of a group of redlamps RI, R2 and R3; and then one of a set j; of green lamps G1, G2 andG3 in succession at predetermined intervals. These lamps are mounted ina casing and are associated, asset forth in my prior application forpatent upon out, in such a manner as to bring a-new lamp such as aspring, not shown, into position to close a circuit from the lead 6through a conductor l6, switch 15, conductor", the windings l8 and leadH] to the return conductor I0.

The windings 18 represent a motor which is connected to a rotary supportcarrying the red lamps, which, for example, are three in number, but ofcourse they can be more or fewer. As soon as current flows in the motor,the support is actuated to shift the lamp R2 into contact with theterminals r; the motor 18 being coupled to the support 8 by suitablegearing not shown herein. The motor has one terminal connected to thefixed terminal 20 of a switch, the movable member 2| of which is unitedto the conductor 22 attached to a conductor 24 leading to the supplyterminal I. This switch arm 2| is normally held in open position by acam 23 and can be actuated by a spring, not shown, to engage theterminal 20 when the cam permits. The arrangement is such that the cam23 allows the switch to move to closed position as soon as the support Shas turned far enough to connect in the lamp R2 between the terminals1'. The motor and the support S then rotate no further. The motorstopsas soon as the new lamp is connected, because the coil M is thendeenergized and the switch I5 opens. But a circuit to keep the motoralive is closed. when the switch 2| again engages the terminal 20. .Thecam 23 is geared to turn one complete revolution while the support Sturns through only a quadrant. As soon as the lamp R2 is in circuit, thecurrent flows therethrough and deserts the coil l2 because theresistance II is too great. The solenoid I4 is thus deenergized and theswitch l5 opens. The coil of the motor I8 then receives no more current,but the switch points 20 and 2| are in contact. Therefore, current canflow from the terminal I through the wire 24 to the switch points 20 and2| and through the coil [8 back to the return wire Ill.

The coil 9 is not enough to energize the secondary circuit containingthe switch-closing coil I4 by itself; and this coil I4 is not energizedtill the primary coil l2 receives current. The current flowing in thecoil 9 during operation of one of the lamps RI, etc., only primes thecircuit containing the coil l4 and makes this circuit active morequickly when a lamp burns out.

In case all the lamps of the red group have been destroyed, the shiftingof the support S will only bring one of the defective lamps into,position when the coil [4 closes the switch 15 and current is suppliedto the motor coil l8. Hence, the circuit will not be established acrossthe terminals r-r. At this stage, however, the support S, which carriesa conductive segment in the right place, bridges two terminals r--r, oneof which is united to the wire 24 and the other to a wire 25, which runsto a-lead 26 connected to a coil 21 adjacent the switch I. This coil nowopens the switch I, and the circuit of the coil 21 is completed throughthe wire 28 back to the conductor H]. No more current is now supplied tothe burnt out lamp terminals rr.

The circuit also contains an amber lamp supplied from a terminal Aconnected to the same timer as the terminals I, 4, 5, to light upbetween the green and red signals. When the circuit for the amber coloris closed current from the line flows to the timer, the terminal A, lead39, switch point 31, switch blade 38, held, as by a spring, not shown,against the point 31, lead 40, the amber lamp, and wire 28 to the returnwire Hi. When, however, all the lamps of the red or green group areburnt out, this amber lamp is made to flash repeatedly to indicate thatreplacement is necessary.

Whenthe coil 21 opens the switch I it also pulls the switch blade 38against another switch point 36 on the side opposite the point 31. Somecurrent in the wire 26 now flows to wire 3| and a fixed terminal 32,which is engaged by a switch blade 33, held against it by suitablemeans. The switch blade is moved up and allowed to drop by a toothedwheel 34, operated by any suitable means whenever a set of lamps is usedup. When the switch is closed and opened by the wheel 34, current flowsintermittently through a wire 35 to the fixed terminal 36. The terminal36 is joined by a wire 39 to the amber lamp, which now flashes till theattendant corrects the condition by taking out the burnt bulbs andreplacing them with new ones.

The same action occurs when a lamp in the green group burns out, or thewhole group is destroyed. The circuits and switches for this group aremarked with corresponding numerals distinguished by the addition of theprime mark. The timer allows current to flow to the terminal 4.

The resistance H is only a blocking resistance to prevent the relaycircuit associated therewith from operating till failure of theilluminating de- "vices takes place.

Having described my invention, what I believe to be new is:

1. An energizing electric circuit comprising a device for consumingelectric current, a movable support for the device, supply conductorsleading to said device, a relay circuit associated with said circuit, anelectric motor, a circuit therefor connected to the relay circuit, meansconnected to said supply conductors for maintaining said relay circuitinoperative except upon failure of said device, the motor being coupledto the support, a switch in said relay circuit to connect saidconductors to said motor circuit upon operation of the relay to causethe motor to actuate the support, another circuit leading to said motor,and means operated by said motor to close said other circuit when therelay opens and the motor stops.

2. The energizing circuit as set forth in claim 1, wherein said relaycircuit is operatively connected to said supply conductors, and saidmeans for preventing operation of said relay circuit is a blockingresistance.

3. An energizing electric circuit comprising a device for consumingelectric current, a movable support for the device, supply conductorsleading to said device, a relay circuit associated with said circuit, anelectric motor, a circuit therefor connected to the relay circuit, meansconnected to said supply conductors for maintaining said relay circuitinoperative except upon failure of said device, the motor being coupledto the support, a switch in said relay circuit to connect saidconductors to said motor circuit upon operation of the relay to causethe motor to actuate the support, another circuit leading to said motor,and means operated by said motor to close said other circuit when therelay opens and the motor stops, said conductors and said relay circuitcontaining means for priming the latter while same is inoperative.

4. The energizing circuit as set forth in claim 3 wherein said relaycircuit is operatively connected to said supply conductors, and saidmeans for preventing operation of said relay circuit is a blockingresistance.

5. An energizing electric circuit comprising a device for consumingelectric current, a movable support for said device, supply conductorsleading to said device, a relay circuit associated with said circuit, anelectric motor, a circuit therefor connected to the relay circuit, meansconnected to said supply conductors for maintaining said relay circuitinoperative except upon failure of said device, the motor being coupledto said support, a switch in said relay circuit to I connect saidconductors to said motor circuit upon operation of the relay circuit, tocause the motor to actuate the support, another circuit leading to saidmotor, and means operated by said motor to close said other circuit whenthe relay circuit opens and the motor stops, in combination with acircuit for opening the circuit of saidsupply conductors, a signaldevice, and means for intermittently energizing said signal device whenthe circuit of said conductors is broken, the relay circuit beingcoupled to the supply conductors, and said means to prevent the relaycircuit from operating being a blocking resistance in one of saidconductors, and said conductors and relay circuit containing means forkeeping the relay circuit in primed condition.

OVILA JOSEPH BLANCHET.

(References on following page) REFERENCES crrm') The followingreferences are of record in the file of this patent:

: UNITED STATES PATENTS Number 5 Name Date 1,708,430 Perdue Apr. 9, 19291,749,444 Rae Mar. 4, 1930 1,955,616 Wallace Apr. 17, 1934 Number

